Viscosity reduction of petroleum



Patented Nov. 30, 1948 TENT OFFICE VISCOSITY REDUCTION OF PETROLEUM MAHOGANY SULFONATE HYDROCAR- EON SOLUTIONS Abraham Moscowitz,

to Delaware N Drawing.

This invention relates to new and useful improvements in the viscosity reduction of petroleum mahogany sulfonate hydrocarbon solutions.

Petroleum mahogany sulfonate solutions in oranic solvents of the water immiscible tvoe are used for a variety of purposes such as wetting agents, emulsifying agents and the like. Ordinary petroleum mahogany sulfonates impart to their solutions a relatively high viscosity. In some cases this high viscosity is not critical regarding the purposes for which the sulfonate solutions are to be used. There are, however, many cases in which a relatively high viscosity is undesirable or detrimental to their intended use or application. This is, for example, true in textile processing such as of Wool, Worsted, rayon, viscose or the like in which the various processing steps involved in the conversion of the raw materials into fibres, the formation of the fibres into threads and the weaving of the threads into fabric, require the presence of a lubricating agent having a Saybolt viscosity of below 600 and preferably below 300 seconds Saybolt at 100 F. The latter is particularly true of textile lubricants used in the processing of synthetic fibres. In the case of textile processing it is for instance desirable to have a hydrocarbon textile lubricant composition with a sulfonate content of in excess of 28% mahogany sulfonates so as to render the composition not only readily and spontaneously emulsifiable but also to make the same readily wettable or rewettable on the fibre to thereby impart to the textile material substantial self-scourability. Hydrocarbon solutions of the textile lubricant type and containing in excess of 28% of petroleum mahogany sulfonates possess, however, a viscosity far in excess of 600 seconds Saybolt at 100 F. and usually a viscosity in excess of 1000 seconds Saybolt at 100 F. For this reason it has been necessary in the past in such cases to limit the sulfonate content to a maximum of approximately in order not to exceed the usable viscosity for textile material treating purposes. Another example is the use of petroleum mahogany sulfonates in the compounding of cutting oil bases in which the rela-' tively high viscosity and tackiness imparted to the composition by the sulfonates is an undesirable aspect interfering in many respects with the proper ease of application and use.

The relatively high viscosity of petroleum mahagony sulfonates in organic solvents is normally not subject to reduction by the addition of relatively low viscous diluents or thinning agents. This requires agents of such relatively low vis- L. Sonneborn Son New York, N. Y., assignor s, Inc., a corporation of Application November 23, 1946, Serial No. 711,834

'10 Claims. (01. 260504) v 2 cosity that they interfere with the lubricatin properties of the composition. Furthermore, these solvents are then of the type which easily evaporate. This is particularly critical in the case of textile treating materials since the use of such thinning solvents will leave behind on the fibre upon evaporation a viscous sticky impregnant without adequate lubricating capacity on the-fibre and will also interfere with the scourability of the impregnated material. On the other hand, thinning with a solvent of the lubricant type diluent will not obtain the desired result as it is necessary to add so much of the diluent as to bring the sulfonate content to below that necessary for adequate emulsification or other purpose for which the composition is designed.

One object of the invention comprises inter alia the viscosity reduction of a petroleum mahogany sulfonate organic solvent solution. This and further objects of the invention will appear from the following description.

In accordance with the invention a suitable petroleum mahogany sulfonate solution in an organic substantially water immiscible solvent for said sulfonate is reacted at a neutral to acid pH with chlorine in amount and for a period of time suificient to appreciably lower the viscosity of said solution and preferably by at least one-third.

The solvents that may be used for this purpose should be substantially neutral to chlorine action and should be substantially liquid at normal temperatures. Suitable solvents that may be used in the practice of the invention are, for instance, petroleum oil distillates or any fraction thereof, benzol and its homologs, naphtha, carbon tetrachloride, tetrachlorethane, chloroform, etc., and in general any aromatic or aliphatic or aryl or aralkyl hydrocarbon or hydrocarbon mixture including their halogenated derivatives of the aforedescribed character and nature. In

many cases, particularly where the solvent is tobe removed after the viscosity reducing treatment, it is desirable to have the boiling range of such solvent sufiiciently low to permit removal in the customary manner such as by distillation in vacua or otherwise without causing thereby decomposition of the mahogany sulfonates. In such cases it is of advantage that the boiling point be so low and preferably between and 250 F. as to enable the removal of the solvent at ordinary temperatures without the necessity of re-' sorting to vacuum distillation.

The petroleum mahogany sulfonate which is subjected to the viscosity reduction is normally.

one derived from the acid refining, with fuming sulfuric acid, of a petroleum oil distillate stock under sulfonating conditions of acid amount and temperature in accordance with conventional refining practice. In such conventional fuming sulfuric acid refining an oil layer and acid sludge layer are formed, the former containing dissolved therein petroleum mahogany sulfonic acids 001- lectively referred to as mahogany petroleum sulfonic acids. These are recovered from the oil layer in accordance with conventional methods in the form of solutions of these sulfonic acids or their salts (the latter being collectively. termed petroleum mahogany sulfonates) in a: portion of the oil relatively tenaciously occluded by these sulfonic bodies. This occluded oil isgenerally referred to in the art as retained oilj The-1 etroleum sulfonic acids or sulfonate oil composi tions normally contain about 30 to 35%:ofretained oil and 65 to 70% of the petroleum mahogany-sulfonic material. Dependingupon the type andorigin of petroleum oil distillates from which these sulfonate-oil solutions or stocks are derived they contain sulfonates of varying averaged molecular weights. For convenience therefore-the sulfonate stocks are identified by their averagemolecular weights. Thus, at 420 or 450 sulfonate stock is a stock in which the sulfonates have an average molecular weight of 420 or 450 respectively. p

In the practical application of the invention the crude mahogany sulfonate in the organic solvent solution is contacted with the chlorine by for instance passing the same into or through the solution until the desired viscosity reduction is obtained whichmay be ascertained by the drawing of periodic samples and the examination thereof on a suitable viscosimeter. Maximum viscosity reduction may be accompanied bycolor increase. In such case a suitable color reducing after-treatment may be of advantage particularly when the composition is intended for a use in which its tinctorial value is of importance as for instance fortextile use. Such color reducing treatment may be accomplished by a suitable absorbent or by: solvent extraction. Color-reduction to a Lovibond color value (10% white oil solution /2 cell)- of less than 8B and preferably down to 2-3R' is usually desirable in such cases.

The chlorine reaction or treatment may be carnee. out at a pH of from 5 to" '7 and preferably of from 6 to 7. If necessary the solutionimay be acidified with a suitable acid such as'HzSO4 to the desired pH. It is recommended that excess aciditybe avoided as it may be detrimental to the efficiency of the viscosity reduction and mayfurthermore give rise to an undesirable partial decompoe sition of the sulfonates. In most cases it'is preferredto use the sulfonate hydrocarbon solution in its ultimate application in a substantially neutra1 or slightly alkaline form. For this-reason the chlorine reacted solution should be neutralized by suitable amounts of alkali. Such neutralization may be accompanied by a slight increase of the viscosity from that of the acidsolution. Such in 'crease of viscosity reversion, however, is usually sufficiently small so as not to interfere withthe ultimately desired reduced viscosity of the final composition. I

When proceeding in accordance with the invention it is recommended and sometimes necessary that the petroleum mahogany sulfonate hydrocarbon solution be ultimately contacted withthe chlorine in the presence of relatively small amounts of water. Normally: a minimum? of about 1 to 1.5% of water by weight of sulfonate in solution will suffice for this purpose. Ordinarily larger amounts of water are not critical except to the extent that they might constitute an unnecessary diluent -for thereactants, thus impeding the ready viscosity. reduction of the solution.

The temperature of reaction is ordinarily not critical. The reaction, however, may be facilitated by increasing the temperature to for example a preferred temperature of from 120 to 200 F. This is particularly desirable with more heavily viscous solutions as the higher temperature will increase the fluidity of the solution, thus permitting. more intimate contact between the reactants.

The extent to-which low viscosity values may beobtained depends, at least to some extent, upon the type or origin of the petroleum mahogany sulf-on'ate selected for the treatment. Ordinarily higher average molecular weight sulfonates possess a higher viscosity andthe resultinggviscosity. aiter treatment is usually commensurately higher than--theviscosity after treatment of a' comparative: sulfonate hydrocarbon: solution which before treatment possessed a relatively. lower viscosityxand in which the -sulfonate ha-d a lesser average molecular weight.

The" ratioof petroleum mahoganysulfonateto solvent is, as arule, notcritical -except that-it is desirable'to so adjust the-ratio that the viscosity-of the solution is sufiicientlydow at thedesired o-r-se lected temperature of treatment topermitthe in timate contactibetween -the:reactants; In most cases, however, ra ratio of mahogany. sulfonat z-tosolventof substantially 2:to l -(byweight) will givesatisfactory: results. Sulfonate concentrations above 70 to 75% sulforrate content are normally: not desirable for direct reaction withoutsuitable extension; As a mode of" agitation; any: conventional method such as stirring; airblowirig,v shak-- ing, etc; maybeused.

As above pointed out, the viscosity reducing reaction in 'accordancewith the inventionmay; be carried out with anorganic solvent solution containing.-' relatively; high concentrations-L of petroleummahogany sulfonate. In .thiscasethe resultantiproduct is: awoncentrate" which in many cases" must be thereafter adjusted by the addition of organic solvent material of suitable viscosity; such as a suitable lubricant hydrocarbon; to the requisite petroleum :mahogany sultonatercontent desired for the specific purpose-forwhich the-composition isitobe-used; Thus,- for. instancaif it is desired to uitimatelyproducea textile'wtreating toil having in excess of 28% petroleum mahoganysul innate-and aviscosity of less than 600- seconds- S'aybolt-at F., a concentrate having-:in excess of 40% and usually between 60 and 65% sulfonate;v is r first obtained after the viscosity: reduc'ng reaction in accordance with the invention, which product-maybe then extend'ed' by the addition of a suitable lubricant hydrocarbon such. as -a min eral pale oil havingia viscosity of '75 seconds-Say-- bolt at'lOO" F; to :a- -sulfOnate content;between-28 and l0%- and a viscosity below=600 secondsssayzboltat--10) F;

Alternatively; the viscosity reducing reaction may be'carried out with an'organic.solvent-solu+ tion of a petroleum mahogany sulfon atealready possessing the requisite final sulfonatecontent-de-- sired and intended for thepurposefor which.the viscosity reduced-product is-to lie-used; Inthat case-it is also. or advantageto select-for the solu tion such solvent. as is desired for: the fin'al prod uct; i; ea if =a' textile lubricatingi oil-is-intended to be ultimately obtained a textile lubricant, having, for instance, a viscosity between 40 and 150 seconds Saybolt at 100 F. is selected as the solvent for the sulfonate. The product resulting from the viscosity reducing treatment is then per se usable after such further refining or purification as may be required-for a textile treating oil.

Though in the operation of the novel viscosity reducing process any of the aforementioned solvents may be used with advantage, I prefer to use as the solvent that hydrocarbon fraction, the acid'refining of which furnished the crude mahogany sulfonate stock and which is carried as retained oil. The crude mahogany sulfonateretained oil stock constitutes as such a convenient mahogany sulfonate solution that may be subjected directly to treatment in accordance with the invention.

Once a petroleum mahogany sulfonate has been subjected in suitable solvent medium to a Viscosity reducing reaction in accordance with the invention, it is possible to remove the solvent if desired and recover the petroleum mahogany sulfonates as such substantially free from solvent. These sulfonates when redissolved in the solvent still exhibit in solution the same reduced viscosity which they possessed prior to the removal of the solvent.

The following example is furnished by Way of illustration and not of limitation.

Example 100 lbs. of a petroleum mahogany sulfonate stock containing about 62% sulfonate and about 35.5% retained oil was used. The stock was obtained from a Mid-Continent distillate subjected to white oil refining with fuming sulfuric acid under sulfonating conditions, in the conventional manner. The mahogany sulfonates in the stock possessed an average molecular weight of 450. The stock possessed a Furol viscosity of 132 at 210 F. and upon extension with a mineral pale oil (75 seconds Saybolt at 100 F.) to a 30% sulfonate content a viscosity of 1322 seconds Saybolt at 100 F. The H2O content of the stock was about 1.5% by Weight of the sulfonates in solution.

The non-extended sulfonate stock was then adjusted to a pH of 6.5 with the addition of concentrated sulfuric acid and chlorine was slowly passed into the stock at a temperature for the stock of about 180 F. The stock was agitated while the chlorine was passed into the same and the treatment was continued until a sample exhibited a Furol viscosity of 48 at 210 F. Upon extension to a 30% sulfonate content with the aforementioned 75 vis. mineral pale oil a viscosity of 410 seconds Saybolt at 100 F. was noted.

The foregoing description is for purposes of illustration and not of limitation and it is therefore my intention that the invention be limited only by the appended claims or their equivalents wherein I have endeavored to claim broadly all inherent novelty.

I claim:

1. Process for reducing the viscosity of petroleum mahogany sulfonate solutions which comprises treating the petroleum mahogany sulfonate solution in an organic substantially Water immiscible solvent for said sulfonate at an acid pH with elemental chlorine in amount and for a period of time suificient to appreciably reduce the normally relatively high viscosity of said solution due to the sulfonate dissolved therein.

2. Process for reducing the viscosity of petroleum mahogany sulfonate solutions which com prises treatingapetroleum mahogany sulfonate solution in an organic substantially water immiscible solvent for said sulfonate at a pH substantially of from solved'therein. l

3. Process in accordance with claim 2 in which said solution is reacted at a pH substantially of from 6 to 7.

4. Process in accordance with claim 2 in which said solution is reacted in the presence of at least 1 to 1.25% of water by weight of sulfonate in solution.

5. Process for reducing the viscosity of petroleum mahogany sulfonate solutions which comprises treating a petroleum mahogany sulfonate solution in an organic substantially water immiscible solvent for said sulfonate at a pH of substantially from 5 to 7 and in the presence of at least 1 to 1.25% of Water by weight of sulfonate in solution with elemental chlorine in amount and for a period of time sufiicient to reduce the normally relatively high viscosity of said solution due to the sulfonate dissolved therein by at least onethird.

6. Process for reducing the viscosity of petroleum mahogany sulfonate solutions which comprises treating a petroleum mahogany sulfonate solution in retained oil at a, pH substantially of from 5 to 7 and in the presence of at least 1 to 1.2% of water by weight of sulfonate in solution with elemental chlorine in amount and for a period of time sufiicient to appreciably reduce the normally relatively high viscosity of said solution due to the sulfonate dissolved therein by at least one-third.

7. Process in accordance with claim 6 in which said solution is reacted at a pH substantially of from 6 to '7.

8. Process for reducing the viscosity of petroleum mahogany sulfonate solutions which comprises treating a solution of in excess of 28% petroleum mahogany sulfonate in a solvent for said sulfonate of the petroleum hydrocarbon type having a viscosity substantially between 40 and 150 seconds Saybolt at F., at a pH of substantially from 5 to 7 and in the presence of at least 1 to 1.5% of water by weight of sulfonate in solution with elemental chlorine in amount and for a period of time suflicient to reduce the normally relatively high viscosity of said solution due to the sulfonate dissolved therein to a point sufficiently low to yield for a sulfonate content in excess of 28% a. viscosity below 600 seconds Saybolt at 100 F.

9. Process for reducing the viscosity of petroleum mahogany sulfonate solutions which comprises treating a solution in excess of 40% petroleum mahogany sulfonate in retained oil at a pH of substantially from 5 to 7 and in the presence of 1 to 1.25% of water by weight of sulionate in solution with elemental chlorine in amount and for a period of time sufficient to reduce the relatively high viscosity of said solution due to the sulfonate dissolved therein to a point sufiiciently low to yield upon extension to a 28 to 40% sulfonate content with a solvent of the petroleum hydrocarbon type having a viscosity of from 40 to seconds Saybolt at 100 F. a viscosity of the extended solution below 600 seconds Saybolt at 100 F.

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UNiTETj STATES PATENTS Name Date Lockwood Mar. 19, 1940 Adams June 3, 1941 Liberthson Jan; 12, 1943 FOREiGN PATENTS 

